子実への同化産物供給不足による高温下の乳白米発生

日本作物学会紀事

植向 直哉¹  稲村 達也³  加賀田 恒³  小葉田 亨² 

[1] 株式会社サタケ;島根大学;京都大学大学院

关键词: Grain;    同化産物;    High temperature;    高温;    Milky white rice kernel;    子実乾物増加速度;    Rice;    コシヒカリ;    Spikelet filling percentage;    充填率;    乳白米;   

DOI  :  10.1626/jcs.73.315

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

Increase in the proportion of milky white rice kernels (MWK) has seriously affected rice quality in west Japan during the last half-decade. Rising of temperature has been considered to be the primary cause of the spread of MWK. It is suspected that a lack of assimilate supply to grains increases the proportion of MWK, because high temperatures during the grain-filling period could increase the grain growth rate without profoundly affecting assimilate production. Our objective was to determine whether MWK in the higher temperature conditions could be reduced if assimilate supply during the grain-filling period met the requirement for realizing the accelerated grain-growth rate. Rice cv. Koshihikari was grown at three locations in western Japan over three years. At one location, plots were covered with plastic-film during the grain-filling period to increase temperature. When the mean temperature ranged between 23 and 29 °Cduring the grain-filling period, the rate of MWK varied between 1 and 16% and spikelet filling percentages (F%) at maturity ranged between 70 and 90%. When the plots were thinned to half density during the grain-filling period, all F% attained a ceiling of 90%. MWK almost decreased to below 6%. Hence, thinning can overcome the lower F% and higher MWK. These results suggested that a lack of assimilate supply to the grains resulted in MWK. Any technique that increases assimilation after the heading will be suitable for decreasing MWK.

【 授权许可】

Unknown